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Nice Map If This Link Works

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Ben Zonia
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Nice Map If This Link Works

Post by Ben Zonia » Sat Oct 10, 2020 1:41 am

Image


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Turkeytop
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Re: Nice Map If This Link Works

Post by Turkeytop » Sat Oct 10, 2020 9:38 am

Doesn't work for me.


I started out with nothing and I still have most of it.

k8jd
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Re: Nice Map If This Link Works

Post by k8jd » Sat Oct 10, 2020 1:48 pm

Nice map ! Shows what I expected for W. and N. Lower MI but higher than I expected for my area in S.E. Lower MI !



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Turkeytop
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Re: Nice Map If This Link Works

Post by Turkeytop » Sat Oct 10, 2020 3:59 pm

I can't see it with the chrome browser, but with firefox I can.

What does the map represent?


I started out with nothing and I still have most of it.

Deleted User 3751

Re: Nice Map If This Link Works

Post by Deleted User 3751 » Sat Oct 10, 2020 8:57 pm

Ground Connectivity



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Turkeytop
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Re: Nice Map If This Link Works

Post by Turkeytop » Sat Oct 10, 2020 9:17 pm

Big Signal wrote:
Sat Oct 10, 2020 8:57 pm
Ground Connectivity

Thanks


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CK-722
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Re: Nice Map If This Link Works

Post by CK-722 » Sun Oct 11, 2020 1:13 am

Remember that this map is based on limited data from around 70 or more years ago. I emailed and talked to Glen Clark until shortly before he passed away, and he and I agreed that it was mainly constructed from Class I-A and I-B measured conductivity, and AM directional antenna proofs of performance beginning around 1940 when stations went directional and increased power, in anticipation of the NARBA treaty that changed almost the whole AM dial in 1941. So it there's a Class I or directional Class III from that era, the data was likely generated from that. Glen and I talked about the "bowling pin" shaped area stretching form near the WLS tower to St. Louis. Glen had worked at WLS and agreed that was how that 15 mS/m area was generated.

Only where stations have since done conductivity measurements are there fairly accurate data. Glen said that some he trusted and some he didn't, some having an agenda of squeezing a station in, or preventing another station from squeezing in or upgrading.

As far as Michigan goes, everyone who has traveled and listened to AM radio knows that the stations in the Western and Northern Lower Peninsula don't get out nearly as well as they do in the lower elevation areas of Southeast Michigan.

The border between 2 and 8 would be much further East, and the 8 to 15 area would just hug near the shores of Saginaw Bay and Valley, Lake Huron, Lake St. Clair, the Detroit River, and Lake Erie. The 4 area near Jackson and Battle Creek would extend to near Almont. And at the local area level, results would vary considerably.


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Rich F.
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Re: Nice Map If This Link Works

Post by Rich F. » Sun Oct 11, 2020 3:59 am

Below is a clip from that map showing the Michigan area in detail...

Image



CK-722
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Re: Nice Map If This Link Works

Post by CK-722 » Sun Oct 11, 2020 10:53 am

I have found that this map corresponds better to measured contour data from recent applications on the FCC website. It also corresponds to the very limited signals on several stations which have disappeared over the years, including WHGR, WBMB, WATC/WSNQ, WCRM/WABX, WDEE, WSHN, etc.

https://www.michigan.gov/documents/deq/ ... 1467_7.pdf

Image


Is THAT where they got the idea for the 486-SX?

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Rich F.
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Re: Nice Map If This Link Works

Post by Rich F. » Mon Oct 12, 2020 2:45 am

CK-722 wrote:
Sun Oct 11, 2020 10:53 am
I have found that this map corresponds better to measured contour data from recent applications on the FCC website....
Does any translation exist of all of those detailed color zones to the units and values of conductivity useful in predicting/analyzing e-m wave propagation in the AM broadcast band?

Should some type of averaging be applied across ranges of zones there? An "equivalent distance" analysis to calculate groundwave fields across terrain paths having such detailed zones might take a relatively long time to do, and may not even be necessary.



CK-722
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Re: Nice Map If This Link Works

Post by CK-722 » Mon Oct 12, 2020 4:07 am

Rich F. wrote:
Mon Oct 12, 2020 2:45 am
CK-722 wrote:
Sun Oct 11, 2020 10:53 am
I have found that this map corresponds better to measured contour data from recent applications on the FCC website....
Does any translation exist of all of those detailed color zones to the units and values of conductivity useful in predicting/analyzing e-m wave propagation in the AM broadcast band?

Should some type of averaging be applied across ranges of zones there? An "equivalent distance" analysis to calculate groundwave fields across terrain paths having such detailed zones might take a relatively long time to do, and may not even be necessary.
And yet that's EXACTLY what they have been doing. And yes, it is harder to do. It's been computerized to at least some degree, but sometimes I would question the curve matching, where the points trail way off downward, and yet a higher value curve is matched. I would think that the subjective aspect of matching could be eliminated with some sort of least square curve matching.

I've looked at at least 50 applications that are online that have plotted radials out, usually to upgrade. One example. WTCM was only allowed to have 2.5 kW using M-3 with a four tower DA array when they moved to 580. I think the proofs alone to 20 miles soon allowed the previous 5 kW limit. When they raised the Regional Channel maximum to 50 kW, and by doing more and more measured radials and extensions of the proof radials done during first initial DA proofs of performance, they were able to go 5, 15, 35, and finally 50 kW.

As far as the colors, you get an idea from superimposing the radials on the different parts of the state, and looking at the legend, you'll see that the darker blue is clay loam, the lighter blue has more sand and gravel, the pinks and purples to progressively sandier and rockier soil. Yellow is dune sand. And those soil types correspond to higher or lower conductivity.

I think some of the signals that convinced me that the real conductivity was regionally less was comparing the signals of WWJ 950 with 5 kW to WHAK 960 with 5 kW, and WHGR 1290 with 5 kW to WOIB/WLBY 1290 with 0.5 kW.

Some of the plotted radials in the applications that crossed in the Gaylord and Grayling areas were 0.1 mS/m. And the rest of the radial lengths were no more than 3 in the 8 map region.


Is THAT where they got the idea for the 486-SX?

Same (x, y, z), different (t)

Your bullet missed my trial balloon.

RTN Price. Not guaranteed. As of 12:30, 157.71 Down 0.22.

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CK-722
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Re: Nice Map If This Link Works

Post by CK-722 » Mon Oct 12, 2020 9:53 am

Rich, did you ever see the FCC M-3 Maps for Hawaii and Alaska? They really didn't put much effort into those. It's basically 4 in the coastal areas, and after going a few miles inland, it's 2. It's kind of like that in the Northern Tip in the Lower Peninsula, at a further first approximation. The old map is shown in the circa 1947 NAB Engineering Handbook. You can find it at the American Radio History Archive site. It shows that Northern Tip portion as 4 mS/m, and remember that almost all the AM stations in that area in and in that era were in "coastal" areas, Lusington, Manistee, Traverse City, Petoskey, Cheboygan, Rogers City, and Alpena. So that might explain the 4 assumed for the whole region. But further inland, it's definitely much worse. Houghton Lake, Grayling, Gaylord, etc.


Is THAT where they got the idea for the 486-SX?

Same (x, y, z), different (t)

Your bullet missed my trial balloon.

RTN Price. Not guaranteed. As of 12:30, 157.71 Down 0.22.

Artificial Intelligence is a Child that needs a Parent to guide it through.

Rich F.
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Re: Nice Map If This Link Works

Post by Rich F. » Mon Oct 12, 2020 10:49 am

CK-722 wrote:
Mon Oct 12, 2020 4:07 am
... Some of the plotted radials in the applications that crossed in the Gaylord and Grayling areas were 0.1 mS/m. ...
That value appears suspect, to me. Can you see anything on the map of Michigan geographical topology zones that reliably would support such a reality?

Did the fields improve along those radials after they crossed beyond that segment having a "0.1 mS/m" value?
---------------
I have measured the field of WJR at an open, clear site about 5 miles East of Saginaw using a calibrated FI meter, and it was very close to the predicted value for a conductivity of 8 mS/m for the entire path length. Might the many different soil types for that radial on the Michigan topology map lead to a different result?



CK-722
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Re: Nice Map If This Link Works

Post by CK-722 » Mon Oct 12, 2020 11:46 am

Almost all the AMs in Northern Michigan inland from the shores of Lake Michigan have been deleted. I believe that is one factor. I don't doubt that much of Southeast Michigan, with the exception of the ridge that passes through Oakland County and other nearby Counties where it falls to ~2-4, is fairly close to 8. I measured a bunch of stations that cross that region, and they were all well below M-3 prediction, like 1/4 to 1/2 the predicted field strength, and considerable Winter Summer variation. The only time it came anywhere near the predicted field strength. was one morning when it was -15 degrees Fahrenheit, and I'm not sure that it wasn't CH skywave increasing it. That was when I had been loaned 2 separate field strength meters that were within 2% of each other. Even WXYT was way below predicted where it crossed the edge of that region. WWJ was much closer to M-3 prediction, over similar levels of development.
Last edited by CK-722 on Mon Oct 12, 2020 1:11 pm, edited 1 time in total.


Is THAT where they got the idea for the 486-SX?

Same (x, y, z), different (t)

Your bullet missed my trial balloon.

RTN Price. Not guaranteed. As of 12:30, 157.71 Down 0.22.

Artificial Intelligence is a Child that needs a Parent to guide it through.

CK-722
Posts: 1284
Joined: Sun Dec 16, 2018 3:53 pm

Theoretical WOOD WCCW vs. Real Measured Conductivity

Post by CK-722 » Mon Oct 12, 2020 12:50 pm

Here's the WOOD application exhibit showing the WCCW measured conductivity. The 0.1 mS/m areas corresponds to a direction toward Houghton Lake, where there was a small amount of overlap using M-3 with the existing WCCW at the time, from the WOOD proposed facility.

Whatever the agenda, and the "real" conductivity, the fact remains that AM signals from the North of West Branch, Houghton Lake, Roscommon, Grayling, and Gaylord region never got out anywhere near what M-3 would predict. WOIB/WLBY 1290 has a better signal with 500 watts than WHGR had with 5000 watts.

And as it turned out, WOOD from the new site would have had no overlap anyway. Had there been conductivity studies done on the new site before they filed the application, it may have influenced whether they proceeded. Undeniably, WOOD lost a lot of areas that had a decent signal with 5 kW nondirectional, that don't with 20 kW directional. This necessitated the use of a simulcast with WMUS-FM/WOOD-FM 106.9 in Muskegon to fill those areas that were lost.

We on this board and its predecessors predicted almost all of these results, but of course, what do us hayseeds know? Lesson for today: Listen to knowledgeable hayseeds.

This is what happens when you go by 70 year old M-3 maps, and dismiss reality.

https://licensing.fcc.gov/cdbs/CDBS_Att ... &exhcnum=1


Is THAT where they got the idea for the 486-SX?

Same (x, y, z), different (t)

Your bullet missed my trial balloon.

RTN Price. Not guaranteed. As of 12:30, 157.71 Down 0.22.

Artificial Intelligence is a Child that needs a Parent to guide it through.

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